Michael Niedermayer <[email protected]> added the comment:

On Tue, Jun 30, 2009 at 11:11:06AM +0000, Reimar Döffinger wrote:
> 
> Reimar Döffinger <[email protected]> added the comment:
> 
> On Mon, Jun 15, 2009 at 09:07:11PM +0000, jxself wrote:
> > New submission from jxself <[email protected]>:
> > I am trying to transcode a .vob file from a DVD to a .mkv file 
> > containing Theora video and Vorbis audio. The problem that I 
> > encountered is that the resulting file looks like it's playing twice as 
> > fast as it's supposed to. Sample input file has been placed at 
> > upload.ffmpeg.org/MPlayer/incoming/jxself.
> > 
> > jason$ ffmpeg -i /Users/jason/Movies/TV\ Shows/Holding\ 
> > Area/KUNG_FU_PANDA.VOB -f Matroska -vcodec libtheora -ar 44100 -ab 128K 
> > -ac 2 -acodec libvorbis ~/Desktop/test.mkv
> 
> MPEG input unfortunately is essentially variable frame-rate data, which
> for what I can tell is not possible to encode with libtheora.
> Which means you always have to give a frame rate for encodes with
> libtheora.

-vsync 1 should work as well

> There is also a hack that avoids the issue, but it is likely to cause at
> least as many issues as it solves:
> Index: libavcodec/libtheoraenc.c
> ===================================================================
> --- libavcodec/libtheoraenc.c   (revision 19305)
> +++ libavcodec/libtheoraenc.c   (working copy)
> @@ -237,6 +237,9 @@
>      }
>      memcpy(outbuf, o_packet.packet, o_packet.bytes);
> 
> +    // HACK: does not take codec delay into account (neither does the 
> decoder though)
> +    avc_context->coded_frame->pts= frame->pts;

i dont mind that being commited, theora is crap anyway, thats not going to
really make it worse

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates

----------
title: DVD NTSC video plays twice as fast when encoded with libtheora -> Video 
Plays Twice As Fast

_____________________________________________________
FFmpeg issue tracker <[email protected]>
<https://roundup.ffmpeg.org/roundup/ffmpeg/issue1197>
_____________________________________________________

Reply via email to